WtniKrt ofWalg P.Miifett, Basin (kvcloEnwit Study Dawrtmcnt i^yiJw Batm Rjtnnrimw^e ?|uie Study THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN RECONNAISSANCE PHASE MASTER PLAN Volume [V; Water resources A- Hydrology FV Hydrogeology C-Dains & Hydropower D IrrigationPreface The dry basins recoeuioisMnce phase study hM been conducted by the experts pulled out from the basin development study department Data collection and rapid field visit was made for three dry basins simultaneously viz. Ogadcn. Aysha and Denakil, between June and August 1999, then the report production was almost completed in May 2QOO. llic icpiut i> divided ui iu VI volumes made up from works ooiiducied Jului^ die study phase FjcIi volume has sections depending an the details of the sector Volume I hvouiivc Sumrtwn Volume fl Natural Resourc es Volume HI .AEriculture Volume IV Water Resources Volume V Sodo-Ewnomy Volume \7 F.nvironmenl las! of expert* produced these report are; Eyilachew Yitayew Abebe Gulma Solomon Aicngistu Am.ire H'Selassie Fckahnicd Sinlayehu Ttlahun Mckmnen Worku isavas W.Mariam '"liium AdmJSU Belay Tcgcgn Wubshei Alejnayehu Abaci G.Medhin Crnshu Kebede Vtelaku Abebe Gdachcw Beyene Ycyesus Work Bckclc Geology and Mineralogy Soil survey and Land evaluation Land usc/Covcr Foreslry and Energy Wildlife and Tourihiu Agronomy Livestock. Rango land. Apiculture and Fishery Hvdrology Hy drogeology Dams and Hydropower Irrigation and Drainage Gtoiecnnicis anu Lnuxidutlure Agricultural Eccwrnrnicsi Demography Soil and Water Conservation Environment and Environmental Health . ■ *■ ¥ 7I I i ti -----Dry basins rtwdy project ■Thuiakil Ogaden and Aysha1 Hydrology report. I $99 THE FEDERAL DEOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN INTEGRATED DEVELOPMENT MASTER PLAN PROJECT RECONNAISSANCE PHASE HYDROLOGY 8 ■i M injury of water rew^rte? of Ethiopia December* 1999 I Bllift development nuily depaniHCRlDry baiini Rudy project Dan^ViL O^aden and Aystei/ Hydrology report, im TABLE OF CONTEfrTES CONTENTS EXECUTIVE SUMMARY................ I. INTRODUCTION I I OBJECTIVE .. 2. LOCATION AND PHSYIOGRAP3IV — ....... PAGE Ji ■ ImUI.ii .i.iMiuikiiiiriiiiinmBirfiFiiriiriifliiiiitiiiiiiiiiiifiii.i. mniiHiu 1 3. OVERVIEW OF PREVIOUS STUDIED PROJECTS-.— y 3 EV DS A, MASTER PLAN FOR the development w surface wanit resources in the Awash fas^ HALCROw. TO.. l■■tt■ttWMW•«lt«f■tl I twits IB tlBIII 1.2 EVDSA. Water rlsources development master plan for Ethiopia. WAPCOS, 1990 —J .5 3 I METEOROLOGICAL. DATA ..-..3 3 2 RIVER FLOW DATA i! 1 !■!rmieiiiiijii ii iijib hi II I. IIUI.il Jll.lldlUlkll.l ..IUIU.i .....5 3 3 SEDIMENT TRANSPORTATION DATA 4.0 CLIMATE—......... 6 4.1 GENERAL DESCRIPTION.... iitiitiiaimtiiitii * 4.2 CL IM ATE 0F THE BASIN .... ■f-ifii-irsi-iiii ■■ ibii. 11 iji 1.11 a.i 1 iiii-.i«i.->i»i».. ■ ....... 7 S.FRECI PIT AT LON....... 5.1 N ETWORK/SPATJAL DISTR I BUTION OF METEOROLOGICAL STATIONS .......... 6.9 SURFACE WATER RESOURCE ......... 9 11 7. PROPOSED PROGRAM FOR II PHASE ACTIVITIES, LOGISTICS AND MAN POWER REQUIREMENTS 3 7.1 PROPOSED PROGRAM FOR II PHASE ACTIVITIES I: J 7.2 MATERIAL AND MAN POWER REQUIREMENT—. ft. CONCLUSION AND RECOMMENDATION................................. iitiMinttiiMitim Btvi 1 ■ a^i 1 ■ 111 11.51 IIn’ REFERENCES. i^mmniHiiaiKiii 14 Minisin- <rf ftMJiircEs of Ethiopia ~Ti" Bfliin development study departmentDry bAiim study pnjjacl .'Uariakit, Ogadcn And Ayltw' TABLES Hydrology ftpon, 1999 PAGE TABLE I MATERIAL AND EQUIPMENT REQUIREMENT FDR THE HYDROLOGY SECTION TABLE 2 MAN POWER REQUIREMENT FIGURES FIGURE I "TOPOGRAPHY OF THE BASIN I? 11 PACE 2 Ministry of *aw resources of Ethiopia 7T Basils iieve lopcneni study departmentDry basins study projeei /Danxkil, CJgadrji nnd Aysha' Hydrology report, 199$ Figure I : Topography of the basin 2 _ Basin dcvetapnitHL siudy depanmem 'Ministry of water rewu«« of EthiopiaBasin map oi . j □inn -*r t ______ bOVHliMd fTMM Ina fcfWlri _____ bread ibica I J. ■?F” .Tconilfy bavins Study project flJMUkli. Qptkn and AyitlV Hydrology report, 1999 OVERVIEW OF PREVIOUS STUDIED PROJECTS 3.1 EVDSA, Matter plan for The development of surface Wittr resources io the Awash basin, HALCROW, 1989- tn the report indicated the water resource of lhe Awash basin as a whole. The Aysha basin founds in the eastern sub’Catchmcnt of the Awash basin, with low rainfall and barren tand. The basin situated into 2 rainfall regimes ,'based on The Awash basin rainfall regime classification/ In Awash master plan study report ihrtrt was no indication about the water resource potential of Aysha sub catchement 3Jf EVDSA, Waler resources development master ptun fur Ethiopia, WAPCOS, 1990. The study and masterplan preparation was 10 comprise of thrre phases. The inception phase, the study phase and indicative muster plan preparation. In the first phase of the report preparation the analysis of all implemented projects with respect to hydrological and geological features scdimcniaiion, adequacy of spillway capacities irrigable areas and land suitability, hydropower asspects and envimmcnlal effects were discussed. In the tntriin report, the studies have been mainly directed towards the preparation of the indicative master plan. Most of the studies carried put were used for the formulation of the plan and some of them sen-ed as useful guidelines for detailed planning. The final report marks finalization of the preliminary master plan. All identified irrigation and multipurpose aswell as exclusively hydrpowcr projects have been described, The projects recomended far excution during the next SO years in phase manner have been mentioned. The final report consists of len volumes. Mznisirj- of wiier resources of Eihicpia I Basin developwn^-nc sLudy departrnemQiy twirc Mudj |^jKC il L Ogxfcri Mtd Awh*'_________________________Edj-tfrdQjL>- report, IW Ln [he SLudy identified 4 major basins in Iht Country. Aysha basin belong Io eastern basin. Rased on updated isohyets, aril river basin has been subdivided into different rainfall zones The purpose of zoning is to underhand lhe spatial variability of rainfall, identify areas of higher suitability for ^ate? resources. 11 B 1.1 1 1 T | J J II i. h ■" - L - 4 Ministry of Waner resources of Ethiopia T Eta development study department - 1 - ■« h -. 4 _ I“.Dry j^Miiiw ffuty prajrei /Dmakfl, Cjadwt and Aytiiaf 3, DATA AVAILABILITY il METEOROLOGICAL DATA Hydralngy report, 1999 Source of a]] meteorological dam could be NMSA and FAO. In this report no detailed information regarding the climate of the basin is collected. For general information annual value of basin climate characteristics is included in the report /liALCRO W, 1989/. 3.1 RIVER FLOW DATA In Aysha basin no measured streams ckbsls, therefore the flow data from this basin should not be expected. M 3.3 SEDIMENT TRANSPORTATION DATA Since the basin ha^' tip perennial streams which can be quantified the am&unl of flo'v, ficnv tneaiurcmcnl cwlduol be done. Beside to ibis the esliouiicin of sediment transportation from these seasonal Eijesiiis have been impossible. -y > .■ ■ 3 F Mbiinry olwqfrrmomrecs of Echiupia I B&iin devekipmenrt Mudy dtpsrtmem -------------------Dry t»*jias study pnajttt /D-mfcil, Ogadtn tnd Ayshaf______________________ Hydroxy report, W 40 CLIMATE ' i-. ■ ■■ - 4.1 GEN ERAL DE5CHJ PTI05 The most important Elements for both agriculture and hydrology are precipitation, temperature and evaporation. Precipitation data arc an important input in waler resources studies, in particular for the study of the rainfall-runoff process through which is determined how much runoff results form a certain amount of precipitation on different catchmenls I he other climatic elements /temperature, humidity, wind speed, radiation and sunshine hours are required to estimate plant water requirements and reservoir evaporation. in the tropical bell, variation of climate during the year arc largely associated with macro-scale pressure changes and the air flows related to these changes. The pressure changes are generally driven by the annual oscillation of the Inter Tropical Convergence Zone /ITCZA In Fcbruitry and March the entire country is virtually dry The southern part of the country is covered by the wet regime in April. In may the bell moves northward, and in June it extends further northward, leaving part of the south and south "eastern regions remain wet during July and August In September, (he belt moves southwards and this movement is accelerated, leaving the north and central parts dry. T J. --* ■ ■*. S| ■■ - V lit' J I t ■■ ■■ J ■ 1 ■I r ■ r" ■r » < L. Ministry of wxrrr resources of Ethiopia * BisLn dtvelopinetii study department i’ F ■Dry basins, yudy project /Datiakil. Ogaden and Aysha.1 4,2 CLIMATE OF TH E BASIN Hydrology report. 1999 Aysha basin is included in BWH (hot arid climate). This basin is barren to sparse vegetation with mean annual rainfall of 325 mm (Aysha) and 185 mm (Dawele) ZHALCROW,.! 989/. The maximum and minimum daily temperature arc in the range of 31.3 and 18.2 °C, mean daily temperature over the basin amounts io be 24.8 "C. Mean wind speed over lhe busin is 2.4 m/s, mean sunshine hours 67 % and mean of total radiation rounds to 4&J.0 cal/ertVday The Altitude evaporation relationship region wise expressed by formulas. As the Aysha basin is a part of Awash basin, regionalization of evaporation based on data collected for Awash, master flan. + The basin has regional relationship for estimating evaporation E * 3-831 - 0.979H where H - elevation E - evaporation Since there is no adequate data for estimating PET of lhe basin, this task left for the 11 phase of the masterplan study. Ministry of **ler resources of Ethiopia Basin development jiudy department. ' " ,*-T " - ’. ■’.<■- Dry basins midy pcqjeci .Ttenakfl, Qyaden uid Aysha/Hydrology reporc, ] ?99 5.1 NET WORK/SP ATI AL DISTRIBUTION OF METEOROLOGICAL STATIONS The present network, of the basin i$ not in the stage of fulfilling criteria declared by WMQ. I he atm of the network is to provide a density and distribution of stations in a.region such that, by interpolation between data sets of different stations, it will be possible, for practical purposes, to determine with sufficient accuracy the statistical parameters of the bajic hydrological and meteorological estimates any where in the region /WMOB 1994/. The WMO advises the following minimum densities of rainfall stations for the different physiogrphic units. Region Temperate Mediterranean and tropical zones Flat areas Mounrai nous areas 2 Small mountainous is lands (COQOOkjn ) Arid & polar zones Minimum density, range/knT/gauge/ 600-900 100-250 25 ]500-100000 En Awash master plan report indicated that in Aysha basin exists two meteorological stations one in Aysha town and the other is in Dewetc town. According to the WMO serup of stations density the bassn satisfies the minimum requirement Miniscry of *a?tr reaxirces of Elhiopia Basin developmcmt study department■ll ■ - •‘•■■ita ■'*5' x. * .T? ’ %*•'* • Dry twins study projc«1 /Daru&il, Qjadw ind AyxW 6.0 SURFACE WATER RESOURCE ■ 5 y i ■ • - Hydrology report, 1999 In the basin flows seasonal slreams like Biye Gurger. Kobe, Seblnsa, Lasarat, Ger bale and Dbcdcr, The climate of ihr area radicates scarcity of rainfall at low larid^ inconsequence of this is small amount of flows Due to scarcity of drinking WlJer the people in lhe basin nedd? to fetch it from a very far distance. Sometimes the supply of water assisted by drilling of boreholes around lhe tillages. In Some places paslonatisls construct ponds or bircas to harvest raid to give drinking water for their cattle. Hcikc in lhe basin drought occurs frequently, tit the time of visit of the arcs the rainfall occured after 3 y«rS. The surface water amount is less due Co rarely occurrence of rainfall in lhe basin The less in amount and rarely flowing of streams of lhe basin to depend on waLcr resource could he difficult. Moreover on the WAPCOS report indicated that the surface water potential of the JflSKl is negligible. 1 .* 4 M in is try of water resources, bf Fin ippjg 10 Bjuin devdDp^eflc $budy dcpnnmcn.1Pry bwire thjdy project/DiflakiV pecten and Aysha' Hydro-logy tepart, T PROPOSED PROGRAM FOR [I PHASE ACTFV1TLES, LOGISTICS AND MAT* POWER REQUIREMENT- 7.1 PROPOSED PROGRAM FOR 11 PHASE ACTIVITIES Far the u phase of the study, Lt would be better la consider lhese: Climate - In upgrading and installment of ntctcorological stations the Jew land should be covered tty Lhe program; - Collect daily ramfall record for selected storms; - Produce isoheyla) maps far mentioned precipitation scries scale I ;25O O0O; h - Based on data from selected recorders and maximum annual daily data, rainfall intensity duration neLaLicms will be developed; - Calculate the average monthly PET with available climatic series; - Rcl anon of average annual data ot' prcc i pilaiion and F ET with all itilde wi Li be assessed. 1 f possible, relations can bt used tn estimate average values far areas wiLhouLclimaiic jnaifonv 3” surface water ■1 - Estimate the annual runoff in the catehment based on the available precipitation dau. - RegionsliM the flow senes based qd the Tninfall-runoiF relation; - Survey irrigable sites based on available water resources. Ministry of water rtiources af EOiiopia tl Basin devtlppmcnt shjd^ departmentDry baiirii Mudy project .PanaktL Ognden and Aysh^' 7.2 MATERIAL AND MAN POWER REQUIREMENT Title I Material and equipment rtquiremcnl for the hydrolog)- seel inn Hydrology repcri. 1999 No llcni description unit Qiy Remark I 2 3 4 5 6 7 8 9 10 11 12 !3 office with the necessary faci lilies Leveling instrument Altimtler Compass Planimeter GPS ..'Preferable pocket size' Computer processor greater speed and capacity Printer flaserjcl1 uninttrcplable power system UPS Personal items SiitMJi-jjry materials Topo Map Vehicle Scl nr nr nr nr nr nr nr 1 1 1 i 1 1 1 1 1/* Set nr 2 1 Can he sha/ed with other sec!ions in water resource group- For all skilled man power which a.Te participating in the next phase of the sudy Scale 1:250,000 I siaiion wagon for super vision I pick up tor field work Table 2 Man power requirement No Man power Qty- Remark I 2 3 4 Senior hydrologist Hydrologist Hydrographer Driver 1 1 1 1 Who has an experience on waler resource of arid region Who participated in water resources related projects Who participated in water resources related projects 3 class driving license and good working experience. Minislry of water resources of Ethiopia TT Bafm development study tSepanmentjDty basin; sjudy project I'Danafci I, OgaJtfl and Aysha/________________________ Hyd/olgay report, L999 8. CONCLUSION AND RECOMMENDATION At this level of the study it was tried to indicate the available information regarding water resource of the basin. As it was known adequate information is the accrss to detail investigation of any basin master plan study. In this respect the Aysha basin has no adequate informal ion-, which can be helpful to execute the masler plan study of the basin. - Upgrading the existing mcleorlogical stations, inorder to get better informations for the next phase of the study. - 'the integrated master plan study of lhe basin in the future should indicate all the water resource potential of the basin. M i n i sir)' ef water rmnwdh &f Eih iopu Bmhi dcvelopcnen? department> > Jjjj- k ■ \U . : 7MtJ,',TJ.>rr 1'". "r —— ------------- - - , . ;■!■ ■■ - ; ■■- ■ . . ■ . .■ .,j a -. h ■’-.■...j■■ • ‘■-■!> ; ■JL - . ■ - “ £ > •■ ■ Qry basins study prqjtei ,'Dajiakil, Dgadcn and Aysha'______________________ _______—Hy<-ri l^j,) report^ 1999--------------------------- REFERENCES l EVDSA, 1990, water resource development Master plan for Ethiopia /waler and power consultancy services, India Ltd./, Vol. III. 2. FAO, 1977, Crop water requirements, food and Agricultural organization and drainage paper No. 24. 3. FAO,1997. Irrigation potential in Africa a basin approach. 4. HALCROW. 1989. Master plan for the development of the surface water resources in the Awash basin for EVDSA, Addis Ababa. 5. Lemina Gonfa. may 1996- Climate classifications of Ethiopia, Addis Ababa, Ethiopia. 6. IGADD, 1990. Forum on environmental protection and development of sub regional strategy to combat desertification. Vol. 11. 7. WAR REDOC, March 1996. international works shop, water resources management in drought prone area, Addis Ababa, 8. WMO, 1994. Guide to Hydrological practices, NO. 168, Geneva. 1 J # a*.- 1 .. -■ < * ► * * 1 *r-* ►Lt Ministry of waler reMurce^ gf Ethiopia Batin development ttudy department “ f.1 r . "■4j’ I .JR 4 ° j« B IMinistry' of Basin Ptwlowngnl Study Dewrowrti Avila Eton R*:<mwaric<; F(iay Study THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN RECONNAISSANCE PHASE MASTER PLAN Volume IV: Water resources A- Hydrology B- Hvdroeeoio^v C-Daius & Hydropower D-IrrigationI Table of cntents 1. P h ys ic a I d escri pt ion.. ....................... .......... .......... ..... . ... 2. Geology and geological history.................. ......... ................... 2.1. Quaternary deposit........ ................................. ,......... ............ 2.2. Magdala group ■ ■ >' 1 1 a ■ a 111 ■ ■ ■ s-ra-i a ■ r r r»i - - - - T + a-a a a a a a aa,a a a a a a aa.a.a a a a a a a aa a a a a a a + -aa 2.3. Amba Aradom formation (upper sandstone) 2.4. Afar group............................................................................... 3. Hydrogeology of Shhiile Zone (Aysha sub-basin).„ „ t 4. Water quality ...... ...................................................................... 5. Conclusion..................................... . ............... ........... ..... .1. Physical description Sh.in/le is a zone located at the north extreme of Somali regional state Aysha a small Woreda town, Syo Gurgur, Adigaia, Andibiyu and Dewele are small towns found in this zone. The area lies mostly in the rift valley and is disturbed by uplifted sedimentary and latest volcanic hills. The plain is covered sometimes by bushes and at other times by grass and termite hills as it was obse.'ved on the way to Dewele area. 2. Geology and geological history Aysha basin is covered mostly by Magdala group and quaternary deposites. The geological history of Aysha basin begins with the uplift of the Ethiopian swell that was foriowed by eruption of the trap series and much later by rifting. Quaternary marine deposits are known along the Red sea Coast, the Danakil depression (in the rift valley). The property, location, and rock types of each series and formation is described as follows, 2.1. Qu stern ary depos it It cavers the plain area found South of Aysha and East of Jijiga area. The main formation af the corat reefs includes fossiliferous limestone with minor clastics of conglomerates, sands, silts and days (Tesfaya Chemet, 1993). This formation is the latest of all that were deposited in the basin. Conglomerates, sands,, silts, days, reef limestone Afar group Basalt, subordinate add lava, and ignimbrites Magdala group. Rhyolites, trachites, (rachytic luffs ignimbrtt^ agglomerates, basalts Arnba Aradom formation, clay, silt. sandstone conglomerate ; .j / / f -r 1 !iv :■Figure 1 Shinile area stratigraphy As observed in the stratigraphy shintie area has more young deposits when compared to Jijiga area. Ml 2.2. Magdala group The Magdala group consists of Rhyolites, trachytes, trachytic luffs, ignimbrites agglomerates, and basalts 2,3. Am ba Aradom formation (upper sandstone) It is comprised of lower cretaceous deposits including clay, silt, sand stone & conglomerate {Geological map of Ethiopia, V.kazmin 1972). The sandstones are vanegated quartzose sandstones of fluvial and/or littoral origin (60-150m). Amba Aradom formation is a cliff forming, highly laterized formation {Tasfaye Chemet, 1993). 2.4- Afar group This group includes basalt, subordinate acid lava, and ignimbrites. It is found mostly in the shinile zone. The ignimbrites are well jointed in most cases and massive in some cases. It belongs' (o the upper tertiary period. {Geological map of Ethiopia, V, Kazmin, 1972). 3, Hydrogeology of Shinile Zone (Aysha sub-basin) When referring to the Northern part of Somali regional state, there are three main formations in the Shinle zone covering most of the area. The Afar group covers large part of the dry basin area in Shinile zone. It is dissected mostly by East-west trending faults and occasionally north-south trending faults {Geological map of Ethiopia, V. Kazmin, 1972). This series includes basalts, ferrobasalts. Hawaiiles with some silicic centres near the top. and interbeded unconsolidated sediments (in a total of up to— ■' - . ■ " ■J.' ■..e. about 1000m). Because this basalt is fresh and highly jointed, it naturally has a high degree of permeability. It also has a high productivity where recharge and topographic positions are favourable. A borehole 60-km south west of Aysha yields 5 Msec with a draw down of only 0.7m (Tesfaye Chernet, 1993) The Am ba Aradom formation is the second largest formation that is highly lateritized, in some places in the north like in the area around Hagere Selam where it acts as an aquiclude below the Tertiary volcanics and causes a spring line in between. In other places where it is not lateritized it has high permeability and produces a large number of springs at its contact with the underlying shales. In the southern and eastern parts of the country, the upper sandstone (Amba- aradom formation) doesn’t show latentization and is an aquifer of high productivity (mostly producing springs). Its high permeability is a result of moderate to coarse grain size, loose cementation & limited shale intercalation. The quaternary deposit found south of shinile doesn't cover the area continuously. Il consists of limestone with a high primary as well as secondary porosity and permeability, The clastics of conglomerates and sands can also be important aquifers if found with a considerable thickness and cover large area. According lothe Hydrogeological map of Ethiopia, 1993; there are three major aquifer subdivisions. Extensive aquifers with intergranular permeability, extensive aquifers with fracture and/or Karistic permeability, main geothermal areas with common occurrence of thermal ground water in fractured volcanic rocks and subordinate unconsolidated sediments. The first type of aquifer has high productivity. It covers the southern and eastern part of Aysha town, Most of this formation gives a ground water with total dissolved solids ranging from 500 PPM to 1500 PPM. From the wells drilled from 1972 to 1936 only 50% of them are successful and is supplied by these wells. The average depth of these wells is 90m and the average yield is 5.96 l/s. The deepest well drilled in the Zone is 133m found atIn addition leaching of rocks by percolating ground water is the source of high dissolved solids. This reaction increases where there is young activity volcanic or where the crust is thinner. 5, Conclusion Weil drilling In the region started from 1957 and went on up to the late eighties as the inventory depicts This shows that the well inventory is done before 1990. Therefore, it should be done on all wells found in the region. This applies to the pumping test of wells in the region too. There were only limited test pumping results shown on the well logs, it is known that test pumping results can help to find the safe yield of a well. Hydrogeological map of Ethiopia shows the general condition of the ground water of the area. Fissured basalt and quaternary Alluvial deposits are the main rocks covering large part of the area with some subordinate deposits. As it is clear from the conclusion, the ground water resource is not assessed in an organised manner covering the entire region. Therefore, the next phase of investigation should be done to estimate it. g It is important to do aerial photographic interpretation to identify lineaments and fractures. This can be combined with original hydrogeological maps. □ The well inventory for each town including hand dug wells and springs should be done. q To know the litho-stratigraphic condition and identify the water bearing formations it is useful to do geophysical survey. Even though it is not sufficient to do the survey, electrical sounding seismic and electrical profiling are chosen for hydrogeological purpose. □ Prepare contract document for additional test well drilling and test pumping0 Perform pumping test and drill deep wells where there are no representatrve boreholes to be test pumped. Q The water resource of the area should be estimated and water chemistry analysis should be made. Thus, it is very useful to collect the representative water sample of wells and then send to the laboratory. 0 Hydrogeological map preparation of the basin. £i Finariy the report compilation should be made. Jirjo’oo- UVD TEISIK WlfEU ELTI I iTEItilS Lilt HtliiAimiT :<i^i d:dirt;« ffttecMp TEHSrrE I^LiiFEIS I IT! TRjCTUil iJTD/OI E lESEIC MEMJ4IILITY ttYBROGEBLflCICil 3TIMLS _____ Faults - ------ > Orowdialar mursmcitjnforr+d I bi&gppearqnct point of latirmithllt stream B MijK pridicliTiLp TtEShE L|UlftES TITI High ^dsctbitr L« pr-sdldroilr CUIE1D AljOlftfcS: 1ST! Lflf fttMfrltgf PtituiE HtlhllllTT NUlCTUll BASE IN’LkBMATEnh _____ nttrwtindal boundary ______idiin boun&rp _____ S«d M CEDtEEEKlL IREIS.COSI: V XCQtEVCE DF rillMlL ClfiUlDTHU FRACTUIE1 TQirtNCC EM15 J.’D 31BDEDLNITI WOWlftlTID Hsdirgl-i fl' llfh Toia F’DIRAL SEHOCItlTir HP'JIUC Of ETdlflfLi ■uiSTiT or Titer tgsmcis lYslL tB'i S^lb 'h'MOCEuL.^LLAL Tap I-iRb HM | nH WMIWRIM MH Rl ™ *71U I4MJH*Annex Logistfcs and Man power Table 3 The manpower equipment and logistics af the project in the next phase Item Personnel Amount Man month 1 Remote sensing expert 1 2 Water quality expert 1 ___ 3 Hydrogeologist 3 4iGeophysicist 2 5 Driver 2 Softwares Type of equipment Amount 1 Satellite image processing 1 2 Resistivity interpretation 1 3jSeismicjn!erpretation 1 4 Water quality analysis ; 1 5'Ground water flow modeling 1 Field equipment Type of equipment Amount 1 Tent with accessories 3 2 Generators 2 3 Air fan 3 4 Bed 3 L- CL C S5 6 Mattress 3 Sheets 3 7 Pillow 3 8 9 Blanket 3 Gas lamps 3 10 Paratrooper shoe 2 11 Gowns 2 12 Umbrella 3l Other Amount 1 Topographic Maps Covering the area 2 Arial photographs Covering th® area 3 Satellite imagery Covering the areaTentative work schedule of Dry Basin in Somali Regional State Figure 3: Tentative work Ktetdule for Somali Regional StateID Task Nam® 1 Hydrogeological survey 2 Remote sensing analysis H- 3 well inventory 4 water sample collection £ Geophysical Survey 6 Test pumping on existing borehole 7 Preparation of contract document 8 Drill adltlonal wells » Drilling and test pumping supe-rvi 10 Analyse the field data 11 Hydrogeological map Preparation 12 Final report Preparation. zslcist, Water quality ■ st I rcUogist HydrogeoJogist 13 14 16 ----------------------------------------- ) .References 1. Geological map of Ethiopia, V. Kazmin, 1972. 2 Hydrogeological map of Ethiopia, Tesfaye Ch emet, 1598 3 Hydrogeology and Water Resources of Ethiopia. Tesfaye chemet, 1993 4 Managing and Developing the Southeastern Rangelands, Richard Woodroof. 5 South Eastern Rangelands, Livestock Development Project, AGROTEC, 1974.Ministry ot Wqter Rmputcw. Bhjji Dti'dopmtni Sard* AvQn Bum R^itMiwt Pto-LSmh: THE FEDERAL DEMOCRATICREPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES A YSHA EASIN RECONNAISSANCE PHASE MASTER PLAN Volume IV: Water resources A- Hydrology B- Hydrogeology _ C-Danis & Hyd ropowerj D-Irrigationk ■J = *< V ■l,‘ ■ r ■ x i'* ' - < .. ■ - r - FEDERAL DEMOCRATIC OF ETHIOPIA MINISTRY OF WATER RE SOURCES AYSHA BASIN INTEGRATED DEVELOPMENT MASTER PI. AN PROJECT RECONNAISSANCE PHASE i1 DAM AND HYDROPOWER ■ ?t ■ October 1999 '■ '.+■ j - |M ! .I- L t r I J + I * t■ ' *1 ■*' - r S U- I r'• 7/ ■ b ... ■■f‘ .--■ t ImroductioTi II General description of the project area 1.2 Objectives of the storage reservoir and hydropower reconnaissance - 3 studies 2 Previous Studies- 3. Water Resources -3 3I 32 3.3 Surface waler — Sub-surface Row 3 4 4 4 General Consideration in hydropower development and data needed — 5 4 Detailed work program for the second stage investigation — 5 References ■5 6 1 r■ r + ■* - v r I :k r .., I■ ■* ■■ ■ _i - 4 4 2 * 5 - 9 n .1 £ IAysha Basin L Introduction II General The Ethiopian side of the basin has a catchment area of about 4 312 km The eastern h bounding of the basin is Djibouti Republic and the test Surrounded by Awash Basin. Like Ogadcn basin, Aysha basin contribution to the countries water resources is negligible. The basin has arid climatic conditions and doesn’t have any perennial streams but there are seven dry streams. The mean annual rainfall of the basins is below 400 mm and rhe evaporation estimated to be above 2000mm per year The topography of the Aysha basin is flat with the elevation ranging .from 17 J 4 m.a.s.l on the high lands where Biyo Kobe and Biyo Gurgus dry’ streams commencing place and 450 m a.s.l. in the low lands near Kaklc dry lake 1 2 Objectives of Storage Reserv oirs and Hydropower Reconnaissance Studies 1 CoLection of previous Studies and data such as existing study reports on water resources of the basin, topographic maps with the available scale, transmission line and power Station etc. 2 Review and examination of for all possible reservoir and hydropower sites. 3 Making use of existing hydrologicaJ study and geological study 4. After the preliminary analysis, inventory of existing and potential storage reservoirs on main rivers and tributaries will be considered to get a first hand knowledge of the sites using topo maps field trips to accessible dam riles 5. Based on the above activities, accessibility, distance to the national grid for hydropower projects, and identification of possible dam sites in the basin. 6. Preparation of detailed work program for the second stage investigation 2. Previous Studies Preliminary water resources development Master Plan report for Ethiopia. (EVDSA 1990). The study carried out by WAPCOS (Water and Power consultancy Services). In this desk study Ogaden basin was grouped with the Aysha and Danatal basin based on arid climatic conditionsThe three basins, i.e Ogaden, Dcnakil and Aysha basin were mentioned together In the study as H'the Eastern BHsins The study was conducted based on topographic maps 1:250 000 scale of the basins This study which was not supported by a field trip to the actual basins failed to indicate contribution of individual basins to the waler resource potential of the nalion This situation and the consideration of the three separate basins as a single entity shows- that the study could not conform to the standard required for master planning. 3 Water resources 3.1 Surface water During the field visit no suitable dam site has been identified. The topographic maps available for the purpose of this study were of the scale 1:2SO,MO survey, which is for too small a scale to bo of much practical use for dam site sanction for the determination of the small-scale reservoirs and dam site potential areas the I 2 50,000 topographic maps with the contour line interval oflOOm. cannot be used instead a 1:50,000 mapping is the minimum requirement for this purpose. To develop rhe available waler resources, which is excess run-off from rainfall in the rainy season, river courses have to be blocked in suitable places, forming reservoirs from which waler can be drawn for drinking and small scale irrigation in the dry season Therefore, the study could not come up with small scale reservoir and potential dam sites. For the purpose of irrigation, and hydropower development in the basin, no dams would have to be considered There are some strong evidences that there may not be suitable dam sites. However, these conclusions from Such short field visits may nut be decisive, the main limitation to reach final conclusions at this stage being again the availability of suitable topographic maps and hydrological data, When this becomes available, the (non-existence of suitable dam sites would be verified. 3,2. Sub-surface During the reconnaissance field trip it was observed that the dry stream called Biyo Kobe is wade type. According to the observation during the visit, the local people use the sub-surface flow by using hand dug wells on the stream channel. Where rainfall is seasonal and en-atic building sub-surface flow dams can be a good alternative for water resource development the more common reason for damming +1r jr‘i\ ■ . '< , ...|< ! . ..4 . a. -."■'/1 .. sub'Surface flow is to store water below ground level in the reservoir upstream of the dam As indicated in the above paragraph, topographic map and hydrological data available to the study was not tlte required scale to enable to identification potential sites for sub-surface water development. It is however, thought that sub surface dam development is the most economical and technical way to provide water for rural waler supply and small scale irrigation development in arid and semi-arid region 3.3 General consideration in hydropower development and data needed. There are two ways of developing hydropower potential. The first is io divert the river flow and develop nm-pff-river type hydropower, and i he second is through the construction of a dam for storing water. Run- oflT-river type hydropower development cannot be developed on the river; found in Ogaden basin. Because, the rivers are flowing in the wet months of the year only for a few days. The remaining option thus is developing hydropower through storage To develop hydropower through a storage scheme the following points should be taken into account 1 Availability of suitable dam sites:- Dam sites can be identified either form small scale topographic maps (1 50,000) oriand by field visit. The existing topographic map of the Ogaden basin, however, is of large scale 1:250,000 and identifying dam sites reliably is impossible based on this map. The expert visited the Aysha basin in July 1999 Possible dam sites have not seen tn the Basin 2 Assessment of stream flows: - Due to the absence of Hydrological gagging stations in the basin, there is no a data of estimated annual sediment yield far catchment and monthly stream flows of the rivers. QutefaHOit Due to the fact that rainfall concentrated to a few days of the year only and it is amount also very small, catchment area of the streams are very small, so perennial streams exist, there-to those stream diversion as a basis for year-round irrigation development is not possible Due to shortage o f water, sedimentation problem and unavailability of suitable dam sites development of hydropower in the basin seems unlikely. 4. Detailed work program for the Second Stage investigation 5 -■ ,T4 1 Sites already identified and siudied should be checked on aerial photographs and with helicopter surveys. Various characteristics of the sites win be analysed using appropriate maps, including hydrology, reservoir characteristics, potential generation capabilities in relation to other projects (irrigation) 2. Assessment of demand and load forecast for export potential 3. Collection of information on sub-surface flow dam in the basin for water supply purpose. 4 Sites will be ranked, taking into account preliminary cost per KWA, benefits for other project^ distance from load centre etc. 5 For the attractive sites, assessment geological and geotechnical properties affecting design of dam, power house and sub-surface dam will be made. 6. For previously studied sites, assessment and updating’of existing data will be made. 7. For the selected sites mentioned above, more detailed studies will be including preliminary designs and costing of dams Titles house, Sub-Surface dams and accessibility. 8. carryout seismicity, tectonic, geophysical survey for foundations at proposed dam sites. 9. Investigation for construction materials. References WAPCOS preliminary water resources Development Master Plan Report for Ethiopia (EVDSA, 1990) In this desk study the three basins Aysha, Dinakil and Ogadtn named as the Eastern basinMinim of Water Ramgetk Buin Devtiooaeni Smdv Ekwrtiwrt AY?ta B«sn ELwonnamanM Fhge Scurfy f//£ ££D£7t4Z DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN RECONNAISSANCE PHASE MASTER PLAN Volume : Wafer resources A- Hydrology B- Hydrogeology C-Danis & Hydropower ^-IrrigationAyiha Dry Bam Master Plan Project Rectnoaiaaanje Irrigation A. Draimfig Report 1 Table Of Contents Page Abbreviations 1. Introduction. I III Illi 1 2. Back Ground 1 Ol'VUIB' | | | | ii i i ■ ■ ■ ■ ■ nimiiu ■ ■ ■ uniiBiaati ■ 3 4. Study Approach & Methodo logy. II 3 ■51 Institution^f & Policy 6 Need For D^velQDment . .. . 4 ............... ......... . ............................ ............. 7 7. Description Of The S tudy Area........... .......................................................... ............. 8 7 ] Location & accessibility .................................................. . 8 7.2 Topography& 1-a.nd Feature ...... ............. ........ -........................... ............. 8 9 7.4 Water resource.............................................. ......................... ...... 9 7.5 AGRICULTURE, LAND USE & LAND COVER...................................... ........... 10 T g ........... 10 7.1 Sockj- Economic aspects........................................... .................... ...........1] 8. Existing Irrigation Development Practices.................................. ......... ........ .......... 11 9. Potentials For Irrigation Development......................... .. ............................... .......... 12 Posuiilak Areas Of Small Stale Irrigation. Development Sites......................................14 10. Previous Studies Reviewed............................- „ ............................ 11. Data Caps Of The Study......................................................................................... 15 ■ . ? -- ■' rr ■t - 12. Conclusion S: Recommendation ....... ...................... . , IX Annexes 1 ........ 17 I. Field Tnp Report........................................................ ................................ 19 fl. Terms Of Reference For The 1st Phase Study.............................................. . ...........28 4 J]J. *• « « 14, R cdfelfiflt'fts 11. S - 11. 15. Map u <* « *1 .. .i—1 1 . I.. ;. n] mt US. M ............. 29 - B|- - I tT .1 ' H Th i.« b%, Ministry of Wain Resorcts River Eton Development Studies Department January 1000 a r AJAyilia Pty Basin Muter PIjji Project RccoanaBs*ncc Irrigation St Drainage Report X 1. APS 2. CECE 3. CO-SAERAR 4. EHDA 5. ESRDF 6. EVDSA 7. ha 8. Ips 9. Km 10. L/s 11. LWF 12. m 13. m.a-5,1 14. mm 15. Kl3/5 !6 MOWR 17. MO A 18-NGO 19. NRDEP 20. PET 21. REST 22. SERF 23. SCF 24. SAERT 25. WAPCOS 26. WWCE 27. WWDSE ABBREVIATIONS Agricultural Projects Study. Concert Engineering & Consulting EntCrpris Commission For Sustainable Agriculture & Environmental Rehabilitation for the Amhara Region East Hararge Development Agency. Ethiopian Social Rehabilitation & Development Fund. Ethiopian Valleys Development Study Authority Hectar. Industrial Projects Study Kilometer Litres per second Lutheran World Federation meter meters above sea level mini meter meter cube per second Ministry of Water Resources Ministry of Agriculture Non governmental organization Natural Resources Development & Environmental Protection Potential Evapo-transpiration Relief Society of Tigray South East Rangelands Project Save the Children Fund Sustainable Agriculture & Environmental Rehabilitation for Tigray Water and power Consultancy Service Water Works Construction Enterprise Water Works Design & Study nterprise ■ ■T I* .1 ■ IT *■ - ".’I .■+ •> -J -■ ■ I,’’ - ■ r’.-! r- ' . ■ - ' IL r. Ministry of Water Rerorces River Bsin Development Studies Department January 2000Ayiha Dry B^cjn Muto Plan Project Recqnmimnre [rogation & Drainage Report 1. Introduction This study report is prepared as the result of the reconnaissance study conducted by the Ministry of Water Resources, River Basin Study Department under its recently launched project, the Dry Basin Study Project. The project carried out this study program from June 1999 io Dec- 1999. This reconnaissance level study is one of the first consecutive studies to be conducted, in view of preparing the final master plan for the basin. And as part of the many integrated development studies incorporated in the study, this particular study report deals with the irrigation & drainage part. The study in genera! attempts to give the required answers in response to the issues given in the Terms of Reference. Accordingly; it briefly describes the back ground and objectives of the study in the first section followed by the description of the methods applied in carrying out the study; Institutions invoked in the development of irrigated agriculture and the policies sei by the government concerning irrigation, arc also pointed out. Following this, all previous studies found available arc briefly reviewed. The detail description of the study area ts given including the location, topograpbyh climate, water resources, lancL, and the socio-economic conditions, Most important of aLL the potentials of the area for irrigation development as a pre- bnunary identification together with the existing irrigation practices currently undertaken in (he area are shown & described in detail. The Iasi pages of the report show the data gaps found and suggested means of filling these gaps, followed by the general conclusion A recommendations given at last. Thr field visit report and Tor is also annexed. I■ ■s '■ .- ■ , > K- ■ .i £, i ■» Ministry of Waler Resort*} River Bun Development Studied Department January 2£00Ayatia Csy basin Master Plan Ptojetf Ftgcunnaissajiee tmphon * Draauge Report 2. Back Ground 1 Tn arid and scmi'irid itcji of iJic world, when: the annual rainfall is not sufficiently available, agriculture can not be dependent °n the direct precipitation. Such areas suffering from shortage of rain fall hsve lherefore been practicing the bt of irrigation to make agriculture dependable and productive business, [he World has witnessed the existence of irrigation practice to hicve a long time history recorded since the beginning of civilization. It is however, a recent experience in Ethiopia which started around 19W in a modem way at larger scale level, although > few small scale tndftwngl irrigation has been, practiced some years before. Currently, not mare than ]90,000 ha of Land is tmgated in the country which accounts only about 4% of the total estimated potential ipigabjr area of 3.5tO 4 million ha. The Aysha basin ts the smallest of all Other basins Of the country with estimated area uf about 2,220 kmL The total basin area is characterized by low rainfall, high evaporation/ evapo- transpiiatiork low or poor soil fertility and no or little surface water resource which makes irrigation difficult. In an area where agriculture is th? only economic activity and means of survival, like ihr region in focus, and where rainfall, the most required input without which agriculture can nOl succeed, is very scarce or totally un.witilahk. throughout the year, irrigation will he the only alternative for development. On the either hand, water as the most important resource far applying irrigation, musL be available at any accessible or obtainable taciturn with regard to the land 10 bt rrrijjalcd. With this regard, the Aysfm basin is however, not endowed with all the resources in question in older to apply irrigation for the agricultural activities earned out ip the area, Inhabitants of the basin area arc entirely engaged in 1 pastoral life, rearing of catils. Therefore, the land in this area is mainly to be used for the growing of pasture, although most of ii is considered unutilizable barren land. Ministry ofWiler Resorcw River Bain Devdcrpment Studies Department JuiuLy 2000' . ■. ■■ - -r „■ . Aysha Dry Basin Mister PLaa Project Recanju^wKe Imgrtiga & Drainage Report______________________ 3 In search of relevant informations and data related to any development of irrigation in the basin this study has carried out more or less sufficient investigations and collected as much data as possible. Among the many developments constraints or reasons for being unable to utilize the resources Ethiopia possesses lack of development master plan as (he one to mentioned. The Ministry of Water Resources as a responsibled government body with this regard is mandated for the study and preparation of integrated development master plan for each river basins of the country. Most of these basin studies have been accomplished in (he past few years and recently such a study far the dry basins is launched. The so named ‘ dry basins 1 ls consisting of the (hrec separate basins namely; Ogaden p Aysha and Danakil which are all located in the eastern areas of the country. 3. Objectives As pan of the dry basins integrated development master plan project, this study has its major objective of conducting a reconnaissance survey in the field of irrigation & drainage in the Aysha basin- Of the intended three phase studies to be conducted consecutively, this study is the first phase study and is aimed at accomplishing the following tasks - To collect all existing information & data on previous studies and existing schemes regarding irrigation development in the basin. - To conduct a physical observation at all accessible areas of the basin and assess the potential land & water resources with respect to irrigation development, To identify all potential sites suitable for irrigation in the basin including all alternative methods of water abstraction for each proposed schemes, based on the field assessment and map observation. Ministry of Water Rewreet River Esin Development Studio Department January 2000Aysha Dry Basin Master Pto Project RecauiaiManee brjption A Drannee Report____________________ 4 4, Study approach & Methodology In accomplishing the study ar this level, two major approaches, the field investigation. and office level assessment methods were used. Prior to the field visit, an office level assessment was carried out in search of all available documents {Previous studies, maps, etc.) that arc relevant to the subject of our study. In this office Level study, activities such as, collection of data & information from available studies of previous years, reviewing of these study documents, investigation of potential sites from available topo-maps of scale 1^50,000, etc, were tiiuroughty undertaken. Under this, circumstances, several governmental or non-govemmental officer 3t Addis Ababa that are expected IO operate in (he area in study or super vision of relevant projects, were contacted Io obtain the required data and information!. However, not much information was obtained except one brief note from one of the river basin studies conducted previously by WAPCOS of India, in 1990. ■After rhe office level assessment has been accomplished, the field assessment program was Hum launched to lake a physical observation of the basin and collect first hand information & data from relevant offices and local people in the area. In anticipation to this field visit, questionnaires were prepared inorder to generate all required informations from the available sources. Vising these questionnaires and through other informal discussions, informations were gathered from various responriblcd regional office authorities and professionals. However, the field visit for direct physical observation of the basin was made only to areas that were accessible. <.-i Minutry of W*lr; Rescue* Jtiver Ilsin Deveippmcrit Studies iJeputtniciii January 20WAysha Dry Basm Master Plan Project Rg«HWUtfiance litigation A Efrainagc Rq?on___________________ 5 6, Institutional & Policy Aspects A relevant legislation so far, ax regards water resource utilization in Ethiopia is issued in proc lama tion NO. 92\94 The proclamation contains statements concerning regional and central government responsibilities on water resources; which applies to all water resources, surface or underground with the exception of rniiicra] waters and geothermal deposits. It also demarcates the responsibilities of the central and regional governments in administering waler resources. The central government (the Ministry of V/atcr Resources) is delegated as (he appropriate body for the administration and management of all transboundary rivers and water lhat flows across or lies between more than one regional government. The regional Waler Mines and Energy Bureaus, on the other hand, are responsible for administering the waler resources existing within their respective regions including tributaries to Irans-regkmal rivers. It is also indicated that utilization of pan.s-boundary rivets shall be governed by international treaties. Utilization of inbuiarics of irans- rcgional or trans-boundary rivers shall be dealt with specific directives to be issued by the council of ministers. According to the proclamation, a permit issued by the appropriate authority (Ministry of Water Resources or Regional government bureaus shall be required to use water resources tor irrigation and others. A permit holder has to pay water fees and cha-ror.^ for different consumptive uses and his the obligation of using the water only far the authorized purpose without causing harm to the environment. Likewise, the authority has the. responsibilities of ensuring the water resources Io be utilized tn the most beneficial manner, supervising permit holders strictly to utilize the water in conformity with (he condition of permit, collection of Waler charges and fees and settling of disputes arising between permit holders. Regarding the land issue the policy states that both urban and rural land are owned by the gcvTtiuncnt and will be made available to investors on kasc-holdtng hatk Minhity efWiter Resottcs River lisin DeusLopmcnt Studies Deptrtmenf January 2 (XXFAyiha Dry Ftam Master Plan Ptaject Rwwwinw litigation A Drauag< Report_______________6 Cased Oft Lhc size of land to be irrigated, irrigation schemes in Ethiopia are classified into 3 groups, iiiuncly, large, medium & small awJc. L-ar^c scale schemes include tiiose with irrigated area exceeding lOOha, medium scale schemas include areas between 200 and 3 ha, and small scale schemes are those below 200 ha. Several national institution* (governmental & non-govmwientai) are undertaking lhc irspomibibtics of promoting the irrigation development activities in the country. The fotlowing are concerned institutions involved in the field of irrigation &. drainage in the basin (among other responsibilities.) Central government 1} Ministry of Water Resources It is responsible tn different water resource studies and integrated development master pla preparation for the country's basins including irrigation development. ii) Water Works Design & Supervision Enterprise (WWDSE) Being under the MOWR, it is responsible for the design & supervision of irrigation schemes in the country. iii) Witer Works Construction Enterprise (W WCE) Being under the Mmirtry of Water Resources, it k responsible for the construction of large i medium scale irrigation schemes. ivl Ministry of agriculture ■i Through its agricultural extension department, has limited involvement in small scale urigation development promotion. v) Prime Minister's oflkc, desk of the Somali Region, ft k involved in the follow up offer the study, design and supervision of snudl irrigation projects, in support of the region’. development Activities. Winisey ofW« Rew^ River Bs.n Devdcprnmt 5^ Dcpartrnou' li-r.uary 20OCiAysha Dry Bam Marta Flan Project Rwonr.MS&ance [mgaboh a. Drautagc Rqxjil _________ 7 Regional governments:- Through the following appropriac bureaus regional governments have the mpectiVE powers and duties in relation to irrigation development i) Water, Mints & Energy Bureaus of the regional stale of the Somali This has (he responsibilities of study, design and ccnstruetion of small scale irrigation schemes, ii} AgricuIturaE Bureau of the regional state of the Somali This has the responsibilities of supervising the operation and maintenance of (he small scale irrigation projects constructed by other bodies, through their extension workers, Other NGOs and private investors Although no private sector activity has been observed in the basin currently, any uilereslcd private investor can participate in the investment or deveiopincnl of irrigated agriculture in the area. One NGO Lutheran World Federation OT is currently operating in the basin in the study, design & construction of small scale irrigation schemes. Ministry ot Water Hrwrcei Rlrei Bam Development Shutts Department Junuary MOTAytha Dry Basin Mister Plan Project Recoonaisaanee Irrigation & Drainage Report 6. Need for Development a In spite of the significant or dominant role it plays in the economic sector to the country, agricultural production remains to be at a subsistence level. As in all other parts of the country, crop or livestock production in this basin is characterized by a highly rudimentary method or technique. The application of modem agricultural inputs like fertilizer, pesticide, improved seed. e.Lc., and the use of modem farm machinery & implements are not widely practiced. Similarly, the rainfall in most part of the basin especially in the lower hasin area, is inadequate in amount and erratic or irregular in distribution, and hence is largely unreliable. On the other hand, agriculture in the basin is mainly rainfed. Fot this and other reasons, the agricultural productivity of the area remains to be very low. Such crop failures coupled with the high population growth rate (in other words, high food consumption) will further aggravate the food deficiency in the area or the country as a whole. Therefore, to avert such occurrences of food shortage and ensure sufficiency in food production, the promotion of the existing agricultural practices into an irrigated one, would be inevitable and highly recommendable. In addition to securing the food supply of the country, irrigated agriculture will also play an important role in the supply of products for local agro industries and the production of exportable items which will be earning the country’s foreign currency need. Irrigation development can also play an important role in the generation of employment opportunities and balanced regional development in neglected regional areas. Ministry of Ware; Resorces River Biin Development Studies DepartmentJ r “ “. ‘ .1 V-p ’t h Ay4i> Dry Basin Mala Plan Project RffWruuatfaftM togatori A damage Rcpcni __________________ 9 7. Description of the Study Area 7.1, Location & Accessibility Aysha basin is located in the wjIfth part of the country and Entirety included m the Somali regional slate, Shinile zone. The basin as delineated on a fopo-map of scale 1:250,000 is bounded between the geographic coordinates of 10° 10 N Io 11° 05'N lat and 42? 15 E IO 42?58'E Long. The distinct boundaries of the basin are Somalia in the east the Awash basin in die west & south and Djibouti in the north The basin boundary starts at around 125km north of Dire Dawa on the Dire Dawa-Aysha-Dcwcle route and extends north upto the Ethiu-Djibouti border Etcpirding aecesaibtliiy, the basin is in a relatively heller position compared Io the size of Lhc basin. An all- weather road of about 90 km and the Elhio-Djibuti rail-way line cross right through ihe middle of the basin. Further more, there are also same dry weather roads and rough tracks crossing over the basin area in difierenl directions. 7.2 Topography £ land festur© The Aysha basin consists largely of a plain topography in the middle section and small scattered hills in the north and south-east areas. The northern part of the basin, which includes ihe area starting from some 20km north of Aysha upto the ElftioDjibouti boundary, mostly consist of rocky 4 hilly land feature with undulating topography ranging between BOO A 1100 mas.] elevation- About more than 50km length between Biyo Kcbobc ( a small village 133 km from Dire Dawa) and Adele ( a small Rail way station 15-20 km from Aysha) ties a wide plain topographic land stretched widely left & right. The elevation here ranges between 600 & 9OO masl The southern part consists of small scanned hills and a wide plain land of elevations ranging between 1000 and 1200 m.a.i.1. The land feature in general is characterized by a nearly flat Land on one part and some undulating land feature composing of various dry stream courses dissecting through, tm the other parts. Ministry of Water Resorws River fain DcveLcpment Slmfas Depamritr'.l Junuary 106CAy0ia Dry B*tm 7-3 Climate flan Project RttonnaiMSnce [rTisBii&n & Drauia^ Report w rhe Aysha basin is generally described to have a hot arid to semi-desert climatic nature. Although any recent or past records of meteorologic data are not available, a cough estimation is given for someof its elements, Rainfall being monomodai (occuring once in the year) is generally very low with annual rainfall amount estimated to about less than 400 mm in most pans of the basin, Temperature is very high most of the year. Evaporation similarly is estimated to be high, more than 2500 mm per annum. 7,4 Water Resource Reference could not be made to the hydrologic report of this recent study for it is not yet produced. Therefore, a short information from the previous study by WARCOS and a map reading from a 1:250,000 scale topo-map is taken io tell about the water resource potential of the basin. According to informations. from WaPCOS Study, the surface or ground water yield of the basin from the point of view of its contribution to the country’s water resource potential is almost negligible. There is no any perennial river existing in the basin except a few tracts of dry streams that tome into life during the wet season. About 7 of such dry streams known by name are shown on the map. This include; Kobe, Biye Gurgur, Gerbaie. Lasarat, Seblola, Delad and Debcder, among which the first two are the major ones. Alt these dry streams mostly flow along sandy river beds and terminate into the plain sHndy fields. The only water sources available for use in the community arc these sandy stream beds. A shallow depth digging on these stream beds would produce water that fills the size of the dug hole. Perhaps this would be an indication that flow exist in these stream courses mostly underground in the dry season. Therefore, apart from the wet season surface flow occurring in these streams, the underground flow should also be considered in the full exploitation of the resources available. Minirtry of Water Ftcwrcn River Brin Development Studici Dtputmenl Jur-uarv 2<MOAysha Pty Ruin Mauer Plan PncflOH IteixHMiaiimiM Irrigation ft Drma&c Rtpcn 7.5 Agricufture, Land Use & Land Cover 11 Almost the whole area of the northern pan which covers nearly half of the total basin is characterized by a barren sandy & rocky land of rugged topography, some scattered hills with almost no vegetation cover, The central part characterizes mainly of a sandy plain topographic land with very little or no vegetation cover. The southern part, however, is composed of some scattered hills and plain land of some scrubs, bushes and grass cover. The land in general as already in use (in the southern part) could only be used for grazing and probably for crop production (if water is made available) while the northern part Is unufiiEzable. Agriculture. although experiencing several limiting factors, is however the main economic activity of the study area. Of this activity, livestock development is the major one followed by small cultivation of crops. Only crops of drought resistant such as sorghum are grown in a few scattered small size plots. 7.6 Soils ■ ■ ■ ■ According to the previous study carried out by WAPCOS, 1990, the soils of the study urea are described into three groups of suitability level, marginally suitable, moderately suitable and permanently not suitable. Parts of (he north, [lOrth-wtst, west east &, south top areas arc classified as Nj which is permanently not suitable with several physical limitation for irrigation development. A small part of the central basin and southern areas are classified as $j, moderately suitable with some limitation which slightly reduces productivity, medium to fine textured, slope 0-8%, effective soil cover of I MM 50 cm, none to slightly salinity & alkalinity and moderate co well drained. The north-east area is on the other hand classified as S3 marginally suitable with moderate to severe limiiation which reduce productivity, fine pr coarse textured, slope 0-8%, effective soil cover of 50-100 cm, none to moderate salinity & alkalinity and impeded drainage. ■■ - t■ Ministry of Water Resorcci River Bsin Development Saidies Department limuiry 2000 * ■*».Aytba Pty Quir, Mana Plan Project Rewnnafsince Irrigation ft 7.7 Soc/o Economic Aspects Report 11 The Aysha basin is totally included in the Somali regional state of the Shinelc zone, The area is entirely occupied by the Somali ethnic group. The population covcridisuibution'i is generally very low with estimated population density of not more than 20 persons per km’ am. The economic condition of the area can be over-viewed as generally poor, with low economic resource-, low income, high shortage of food, etc The major economic activity is agriculture to which the whole population is engaged. Inhabitants of the area are living a nomadic pastoral life and are engaged mainly in livestock herding. Cultivation of crops is also rarely practiced. Infrastructural development and public services such as educatinn, health, communication, water supply are generally poor although possessing a better road & railway facility compared to other basin. Urban development is almost non-existent except a smalt sign in the small towns or rather villages of Aysha and Dewele. Only a few organizations like Lutheran World Federation arc involved in very few development activities such as in community waler supply and small scale irrigation development. 4 * r 8. Existing Irrigation development practices Except one or two small scale irrigation, there Is no significant attempt made to promote irrigation development activities in the basin, despite thr fact that successful development in agriculture could not come true without irrigation. The Lutheran World Federation, a non-governmental organization, has designed two small scale irrigation schemes at Biyo Kebobe and Scmcka which are currently under construction. Ministry of Wiier Rworees River Bsiri Developenait Studies Deputmetn Junuuy 2000Ayrba Dry Buin M«?ierPlan Project Reconnaissance Irrigation Drainage Report_____________________ _ The project at Biyo Kebobc consists of ft sub-surface dam across Kobe stream and diverted for irrigating an area of abt 50 ha land downstream. The Semtka scheme on the other hand is designed to irrigate about 40ha land by diversion. Apart from these two small scale schemes, a few traditional irrigation practices are reported to exist in few localities. 9. Potentials for Irrigation Development tuvertigatinn of potential areas for the development of irrigated agriculture, has been the major objective of this study as indicated earlier. Accordingly, all possible investigations from lite available topo’inaps of scale 1 -.250,000, primarily for the availability of the required resources, are thoroughly undertaken. Land & water which are the primary and most required resources for irrigation development are, however, not appropriately available. Topographically plain and suitable land for irrigation may be available where as none of these areas are endowed with the water resource, But the availability of land alone wilhout water cannot be considered a potential irrigation area. Therefore, the basin as a whole is identified to be a low-potential area for irrigation development. However, the need for the use of irrigation in crop production or even in pasture development in the area is very well noticed. To make the area self-sufficient in toed production and earn extra income, the agricultural sector of the economy which is- for the moment the only feasible alternative, should be promoted. And it is only with irrigation that sustainable development can be achieved in agriculture in such arid regions. Large or medium scale development in irrigation is unthinkable. However, small scale irrigation schemes can be introduced in some selected areas, with the use of the available rain water as source of irrigation water. i Ministry Of Water Rewfccs River Bsirt Devetepmtm Studies Dtpartftiem January 2000Aysha Dry Basin Master Plan Project Reconnaissance Irrigation & Drainage Rcpiat 14 Different rain water harvesting techniques can be applied inorder to avoid the existing water shortage problems. It increases the amount of water that can be available from the only available source, the rainfall, and satisfies the crop water requirement of the selected cropping land. With this regard, the following techniques may be suggested. - Run off farming:- This is a system of farming in arid areas, where that portion of the rain water converted into surface runoff is harvested from the sloping uncropped field in the upland or larger area, and made to flow and stored into the soils of the relatively smaller area of the cropping land below. The runoff water is to be collected and directed to the cropping land using bunds and channels provided in the system or through natural wadis. - Micro earth dams:- Small earth dams can be built at appropriate storage sites to trap and store the small rainy season flow tn the wadis and make use of it for irrigating the down stream selected land. The Appropriate sites for applying the above water harvesting methods as small scale irrigation practice, would each be identified in detail in the second phase study. The following 3 sites are indentified as potentially irrigable areas. From these sites about 4300 ha. of land is estimated to be topographically suitable for irrigation if adequate water is to be supplied from the corresponding streams, However, since the flow amount of each stream is not known or availability of water is never expected reliable, the irrigable area estimation should not be taken as a potential figure. It is only the topographically suitable area that can be commanded from th identified diversion sites. In any way these streams may only be capabl e of serving (supplying) small scale irrigation schemes. 3 Ministry of Water Rewrcti River Bun. DtrtloprnEntltudles Dtpannient junuory 24)00Aysfti Dry Buin Master Plan Project ReeonnaiSMoce trrigaiwn & Driiaafce Report Poaalbfa anus of small scale irrigation development Sites 1. Irrigation from Kobe stream IS The Kobe ,LshclK (stream) is a seasonal stream which appears as a surface flow only in the wet season of the year but exists as a subsurface flow under its sandy stream bed. It originates from the small hills of the souihrm basin bonder at elevation 1300 masl. and flows north-ward across a wide plain land , crossing the Dire Dawa- Aysha road near the village of Biyo Kobe and ending up into a sandy plain area around elevation 800 m.a.s.1, A diversion at elevation 1050 m.a.s.1. would have a potential of irrigating about 1300 ba. of plain land down stream on both sides of the banks. As an alternative, a dam site {mostly of a sub-surface dam) may be proposed down stream at elevation 950 m.a.s.1 near Biyo Kobe to store both surface & sub-surface flow and make available a dependable water source for irrigating the down stream field covering an area of about 3200 ha. But currently construction of a diversion scheme is undergoing for rhe purpose of irrigating 50 ha- of land. 2. Irrigation from Biye Gurgur Biye Gurgur shel is a smalt stream, originating from a similar (very near) area where Kobe originates and flows north ward parallel to Kobe crossing a large plain area, which finally ends into the Ethio-Somali border. The shram may be diverted at elevation 950 masl near Biye Gurgur village to irrigate an area of about 2700 ha downstram on the right bank of the stream, Min’isny otWiier Roarres River B jin Development Studies Departiwrn January 2000Aysha Dry B*cn Muter Rin Project keetrnnamaw lrtigricn & Ducuge Report ______________ ]j. 3. irrigation froffl trio otfter streams The other dry streams shown on the tapo-nup, namely, trcrbale, Lasara;, SebloU, Dctad and Dcbedcr art aJI Email in size and flow across the unsuitable toil anas and thus no irrgadon is expected from them. Only Gcrbaje may however be able to inigiit an area of about 500 ha. if small to medium storage dam is to be bufli 10. Previous studies Reviewed Except Ofle Study document prepared by WAPCOS ( Water and Power Consultancy Services) of India, 1990, no other document was found available for review, in this study, only a very brief infematmn in not more than one page, is shown about the general situation of the basin. The source docitment entitled as “A Preliminary Water Resource Development Master Plan for Ethiopia " Vol -H Main Report by WAPCOS ± EVD&A, 1990, produced a study report, combining the three basins (Ogaden, Aysha 4 DanaJd! ) in one report as “Eastern Basins”, This report briefly describes the Aysha basin as an arid area with an almost negligible water resource or irrigation potential, The study generally lacks sufficient data Be. information and detail descriptions about the basin thus not reliable. Muustty of Water Resorees Rjvcr Brin Development Studies Dcputment Jurmary 2000Aysha Dry Bmn Mister Plan Project Rwonnaiawicc Inigahm & damage Report 11. Data Gaps of the Study I7 As indicated culicr, cmc of the major objectives of this study is the collection of data from the study area. It B evident that these data arc not sufficiency obtained as required, and hence data gaps were made m the overall study result Thia is because the field visit was not carried out as intended & planned and first hand information could not be gathered right from some parts of the basin area. Secondly, the data obtained or expected to be obtained from the regional offices and existing study documents were not satisfactory ones. Therefore, it is inevitable that gaps could be made in the data collection of this study. These include: - Lack of topographic maps of the basin arca( Scale 1. 50,000) l“he$e maps were very essential for derail investigation and extraction of more dependable data on the basins physical features. More over, better identification of sites for recommended micro earth dams or other ram water harvesting. could be made al least with such large scale maps. Although these 1: 50,000 scale maps are not still appropriate for identification of strudl scale development sites,, they give at least a belter view of the area. As a means of filling this data gap. a request has to be made to the National Mapping Agency of the making of the required scale maps of the basin. since they are not available at the moment Lack of a tiill field observation data Since the field observation (a field visit in the basin) has not been fully carried out due to its inaccessibility and security problems, the required field cUta were not collected sufficiently. I his gap stial! be filled in the next phase study when accessibility is improved and security confirmed. An serial field visit (with a helicopter flight ) can be made if accessibility vsill remain a constraint. MiW of Water Rae™, fein l^vekpnmt Scudie,Ayihi [fry &uin Matter PIm Project RttOuntiuuKt trriytiM i Dtninige Rrpcft ]g * Incompletion of data gathering & compilation from related study sectors. Data that are relevant to the irrigation & drainage study, hut which are to be obtained from other study sectors, such as. data on soil suitability (from soil Study), waiter availability & quality (from hydrology), crop suitabilityffrom agriculture) tie. are not yet collected. These will be collected and reviewed in relation to irrigation & drainage aspects, in the next phase study. a Ministry of Water Resocees River Bsin DcvtJopmzpnt Studies DtpsflincM January 2WMAytha^Dry Bmn Mmca PttnProject Reaxmiawce tingatovA Drainage Report_____ ]$ Conclusion & Recommendation The study result shown above reveal that the. whole basin area is m great shortage of water resources This waler shortage problem coupled with lhe severe climatic condition of the area, has made irrigated agriculture somewhat difficult. However, the availability of such vast 4 topographically suitable hod couM be untied for cultivation of crops and pasture if every effort is made to make use of the available water for irrigating it in any possible technique. According to the estimated climatic inionnaticMi of the bsrin, rainfall amount is very small, not exceeding 400mm at average, and even worse than this in the far northern parts which is lesa than 200 mm. This amount occurring in an erratic distribution pattern, is never to fulfill the evapotranspiration demand of any crop intended to be grown in the area, The potential evapotranspiration of the area, estimated to be raort than 2300 tnm pcrannum, is much more than the annual rainfall amount. The only means of converting this small amount of rainfall into a useful resource, into something that could be sufficient for growing crops, is by applying a rain water harvesting technique. In doing so, the amount of water collected from an area will be made to flow concentrarcdiy over a smaller area of crop land and stored in the soil profile to be used by the crop until the next flood comes, In general flic study' has tome up with a conclusion that the total basin area is identified to be a low-potential irrigation area in large or medium scale level, due to mainly of water constraint. Except two or three dry streams, iw significant stream flow has been identified- Probably some wadis 3jid dry sandy streams, where underground (subsurface} flow occur, could exist in many parts of the basin. A short period surface flow in the wadis may be observed only in the wet reason while lhe subsurface flow may stay until the dry reason period. Therefore, the cxeteiKc of such, areas could be accounted for the siritabiEry of spate irrigation or run off fanning system, and reservoir irrigation using micro-earth dams and sub-surface dams. Ministry of Wain Resorces Rwa Bwi Development Eludes Department Juiraary 1QO0Ay?hj Dry Rjdin Mi-.tcr Pl*n Project Rworuiiissatnce Cni^ntiutt & Drainage Report 20 As a conclusion, the basin's potential for irrigation development is limited to only small scale level, where the source of water would be made available from either; i) Diversion of spate flow in the wadis or other min water harvesting techniques. ii) Construction of small storage earth dams on existing dry stream courses for intercepting and storing the wet season surface flow, tri) Construction of small sub-surface dams for intercepting and storing the sub- surface water (low in the sandy stream beds. iv) Construction of wells for extracting the ground water resource. *• ■ It is therefore recommended that the above water development techniques be applied inorder to make the required water available for the intended small scale irrigation schemes. Investigation of suitable areas from larger scale maps, such as 1:50,000 should however be undertaken in the next phase study. Since the overall population of the area is largely bound to a nomadic pastoral life and the land is mainly suited for or classified els pasture lancf development in this field will be given the priority. Therefore pasture land irrigation using the above mentioned water harvesting techniques can be practiced for improving the range land condition of the area, h It had earlier been described that adequate field visits have not been carried out due to problems of security & accessibility, Therefore, serious attention must be paid to a reconsideraiion of a field visit program using vehicles or helicopter in all important and possible visiting sites ofihe basin for better observation and data collection. Minisiry <?F Water Resoreei RlvtrBsin Dtve^mcni Studies Dcpartrr.crrt January 2000Ay Ehl Pry Barui MwttrPIg Prajtei Rccn.u.airsan^ Ln-if-arLoji &. !Jrahu e tapo* 21 B Field Trip Report f. Introduction LI General To properly dsvciop and utilize a country's- resources, development master plan is very essential. In this regard. (he Ministry of Water Resources, given the responsibility of studying and preparing master plans for the country’s river basins, has betrt doing its best on the preparation of integrated dcvcopment master plan for many of the river basins- Similar program has been Jnimched recently for the Aysha basin. Since the master plur. preparation is intended Io be accomplished in three phase studies, the first phase or the reconnaissance level study is one of these phase studies which this field trip is committed to. This report deals with lhe irrigation & drainage aspect of the basin considered ns one study sector among the many oihers in the program. The report will briefly show the overall activities Conducted, local areas visited, institutions, and individuals contacted, etc while slaying at held. The field [rip was. carried out from J 8 June. 1999 to 23 July. 1999 which totally took about 20 days. This field program generally covered only those visiting sites that are accessible by vehicle. Since one of the objectives Df the field visit is to collect required dam from (he main data MtttO ie the regions, all the regional & zonal offi « which are c included in lhe besiti are visited. likewise, existing rivers Df the basin and their adjacent land are visited wherever accessible. lh± tnp Wts conducted in group consisting of four members of different professions. 1 M1.I.W .r w.« w P dopglen W „ . |, t OtpTO|t|ir JunfiMiy 200QAyrin Dry Basin Mmef Plan Project RKOfUuhMnee IniaatMWi &. Drainage Rqwrt 1.2 Group members The group members participated in the field trip consist of the following staff of the project. 22 1. Wuhishet AJemayehu 2. Belay Tegegne 3. Abinct G^Medhin 4. Eyilachew Yitayew 1.3 Purpose of the trip Irrigation & drainage Engineer Cann of Hydro power Engineer Geo-technical Engineer and infrastructure Engineer Geologist As a partial fulfilment of the terms of reference prepared for the irrigation & drainage sector of this reconnaissance study,, the purpose of this trip was in general to conduct a preliminary visit to all accessible parts of the basin. The particular purposes include; - Visiting and collecting informations from al] regional and zonal offices found in the basin., regarding all existing studies and project activities Ln the area of irrigation and drainage - Taking a general view of the basin through physical observation of the resources available. - Identifying potential sites for irrigation & drainage projects in the r a basin and justify the map identification for the proper location of both diversion dam sites on the rivers (water sources) and adjacent irrigable land. v ♦ Ministry Of Water K.tSarcM RjvW Bsin Development Studies. Depijrmtnl JununOi1 2000Ayshi Dry Baria Master Plan Ptojrci PccMuiajiante Imgaiian Ji Drainage Rxpc-rt 2. Activities conducted Being arranged as a reconnaissance visit to all accessible parts of the study area, the field trip has come up with the accomplishment of several important activities. The major activities of the trip may briefly be described as follows, ■ Visiting of government offices involved in the field of irrigation & drainage works in the basin. The regional and zonal offices were visited and drscuasicn held wilh concerned officials inorder to obtain required data and informations on existing irrigation schemes and newly proposed or ongoing project studies within the basin. ■ Assessment of other non-governmental and private organizations which are involved in the study and construction of irrigation schemes at regional de zonal levels. * Conducting of discussions with indlvdual farmers involved in irrigation activities. - Physical assessment of all accessible irrigation potential site that have earlier been identified from the available topographic maps of scale 1:50,000 and 1:250,000 In the overall, reconnaissance visit which have been found accessible, only a small portiot of the total basin area have been visited. 1He major liavel route include the following.. I) Addis Abeba - Jljiga ii) Jij iga - Dire dawa iiiii) Dire Dawn - Aysha - Dwelt. ♦ 23 Ministry uf WiMf Reftntt River B iai Devctopmenl Scudiw Department s January 1WJ{) iAy»ha Dr? Basin Mwicr PLm Pftrjwl E™nziakmiQe irrigate & Report 2d Visited Govarnmont Officer M RcguM Zone Tiffwi 1 Water, Mines & Energy bureau Somali • Jijiga 2 « SERF - 3 Agricultural Bureau BL 4 H «k itL Shinile Dint Dawa U th ESRDF ■ JijLEa Among these offices, only the Water, Mines &. Energy Bureau of the Somrii region is found responsible for irrigation wxjrliS but SO far has dotiB nothing in this basin. 2,2 NG □? Contacted Among several NGOs operating in the basin, only a few art involved in irrigation activities. The following offices were contacted during the field trip for search of relevant dit4 ft informations. V Qfflcts Region Zone 1 OXFAM Somali - 2 give the Children Fund UJc^SCF) lb Jijiga - M 3 Lutheran World Federation (LWF) Dire daws - Dire Dawn 4 EUDA Somali Jijiga 2. J Private organizations No private organization involved in irrigation activity his been found in the area. 3. Visited sites Elbayc jVd OT Jlegwn Zone Burette i Somali ■T’ji&B 2 Biyo Kobobe stream M Jijigfl Shtnile 3 Aysha M- Aysha lL H 4 Dewelc M CL Dewele. ■<j MWwy dfWtm Re!tfW! Studhs Depart-------------- Jwyaooo'------------ ■ ■ “1 ' * * !Aysha Dry Basin Matter Plan Project Rmouisawii Lmgqrion. &. Drainage Report 4. G ova rnment Officials Conte cted 25 V- P/acv Name Official Post 1 2 Jyiga Glday Irrigation Team leader Water Mines & Energy £i. Siyoum Agronomist Agricultural Bureau 3 M. Mohammed Project officer ESRDF 4 U - Project Coordinator OXFAM 5 U - iL 31. SCF 6 DireDawa Elias Mohamed Head of Zones Office Agricultuse Bureau 7 !iC Yidcg Area Coordinator LWF Dtredawa r » dL Awlachew Abebe Technical Section head i£ M. S Problems Encountered a I ■ Although the field program has been completed as scheduled., problems of different sorts were however encountered in the course of the trip. Some of these are as shown below. - Accessibility is generally poor for most of the basin area. Because the field visit was carried out in the wet season of rhe year, rivers were filled and roads & bridges were over flooded at some places. This has made some of the accessible sites difficult to cross or sometimes caused delayance in the travel program. Other proposed sites to be visited (identified from topo-maps, especially those located in the eastern tow- lands) arc totally inaccessible due to cither tack of roads or climatic problems. There fore it was not posribtc to have a visit to these areas. - Concerned officials or other resourceful individuals to be contacted for obtaining the required informations, would sometimes be not available at their offices during our visit. We had to waste some time for waiting or otherwise compelled to contact some other persons who have a lesser knowledge of the information we require. - Topographic maps of scale 1:50,0fi0 which are more appropriate for identification of irrigation command areas were not adequately available for the whole basin area, Ministry of Water RttMtes River Bsln Dcvetapnwt Studies bejwnrieni January 2fl00Aysh* Dry- Rji-jn Mailer PLw Project RecciULMiSKiM lrrit-ifi«i i Drainage Fit-part 36 - Some minor problems such as vehicle maintenance, defective roads, elc have caused some delayance in our daily (ravel program. - Group members combinaiion was not appropriate. For instance the hydrologist and hydrogcologist should have been assigned with us {the water resource group) because it could have been very convenient to exchange ideas and discuss matters in site identification work. MlniMry of Water Resdrcw River thin Development Studies Depwnenr Junnwy 2000Bjj_Mi5ta Project Retfxwimncc Mptioft<DgintgeRepy 27 6. Conclusion & Recommendations Every possible attempts have been made to cow the proposed activities of ihe field trip which was Hrnitcd to only accessible areas of the basin. As much information as possible have been collected from concerned offices and field investigations carried out from all accessible sites in accordance with the terms of reference. Howcwr, the area coverage of the field trip was not large enough to be abk io show the full view of the basin. Only the areas along the Dircdawa Dcwele road were visited while other proposed sites could not be visited due to accessibility problem. .1 Therefore, to conduct * complete investigitjon, t° the basin, the following may be recommended. - A helicopter lour program shall be arranged io visit those inaccessible areas of rhe basin. . Topographic maps shall be made available through the Ethiopian Mapping Agency. . Gtwip members drscuMion shall be made especially among, those related Study disciplines Ministry of Water Rewrcw Rivet Bsti Devrlopnwr.1 Scudsss tkpmnwnt lunuary IMOAytlM Dry Elunn MasterHan PiPjKt Reconnaissance inigBBgti& DtainagtRe£CTl Annw-n Terms of Reference for the Reconnaissance Phase study of the Dry Basin Integrated Development Muter plan Study Projed. IRRIGA TION AND DRAINA GE 1. All Existing studies within Ute basin in the area of irrigation and drainage and relevant sectors wiH be collected and reviewed. 2. A reconnaissance visit to all accessible parts of project sites will be done far a first hand information. 3. For the identified irrigation and drainage projects, water resources 4vdlabibhr\ climatic conditions. soil suitability, population density, food deficit, location accessibility etc. will be examined in consultation with the other experts. 4_ Where major storage is required for irrigation development, the location of this will be indicated io the relevant expert for the selection of appropriate dam site. 5. The data gap for die study will be identified, and means of filling the data will be suggested. 6. Work program for the second stage of (he study wfll be prepared, 7. All logistic,. laboratory requirement and other relevant materials requirement for the sector will be identified for (he second, stage of the study and presented. 8. With all the above information a reconnaissance report will be prepared and submitted. 9. The work program for each activity i& given in the overall activity program of this study and submission of the uutpul nil] be in line with thia work program 10. Preliminary identification of potential irtygation sites if possible. of«. R„o.™ fc„r --------T—jSSJAyshi Dry Bann Plan Project Reconnaasanre inylixm * Drainage Report Annei III THE DRY BASIN INTEGRATED DEVELOPMENT MASTER PLAN STUDY PROJECI TERMS OF REFERENCE FOR PHASE II AND ID STUDIES Zrri^aritf/t and Drainage 1. .MI data, tnfomtation & maps relevant to the field of irrigation & drainage study shall be collected, analyzed and existing studies reviewed as to recent information & maps available. 2. All potential areas of irrigation development shell be identified {including those obtained from the reconnaissance study) on the basis of suitability of topography, soils, waler, C-l-C and availability of sufficient waler quantity. 3. The need for major Etoragc danis shall be assessed and indicated to the relevant expert for selection of proper dam sites serving the respective irrigation sites. 4. Field visits ( with helicopter dt vehicles) have to be canted out on selected irrigation sites for further close investigation. 5. .'Ml sources of irrigation waler (surface & ground water) and means of abstraction shall be assessed and identified for all proposed irrigation schemes. AH engineering options shall be compared to select the most appropriate head work. Inter basin ar basin transfer of water sources into potential inigablc land, where (here is shortage of water, shall be considered. 6. Collected data & information available from relevant study sectors like soils, hydrology, agronomy, socio-ttonomy, environment, etc. as analyzed by each sector shall be examined in relation to the proposed irrigation sites. 7 The total project water requirements ( net, Gros and peak season demands) of each scheme must be cstunatcdtealcutated and compared with the available water quantity of each identified source, in order to determine the size of the maximum irrigable area This may include. Estimation of irrigation efficiency, water loasesduc to .evaporation & transpiration (evapotranspiration demand), additional sttwuvc rainfall, other waler demands like leaching, etc. supply from Computation of crop water requirement of possible intensity. cropping pattern, and cropping * 8. 9. applied for each proved scheme, appropriate irrigation system shi From selected potential areas, projects shall be prioritized according to prioritization dL con%7ti^ru] of irrigation (gravitational, pressurizedj-to be criteria for predfeiaibdity smdies The selection be appov^ by el "T k u u . , . pnotltiZatiOn ™”]M1 “-<1 li H I ill Ft-i nfU/nPir r- era1 lwmir.nr Tn An 1The prefcMibjlity studies- contain, 10. I .youS »d pnlim uiuy daigns of th< ^taw. (« »< X hvd.X^ms - -. ; -x cnw ■■» - fe. Ind mfr. All illffliriw design* .W be pr»«><c<l alow»<fe mth *« mon “T 11. pfOfWMh Typki] sample M«b and irrigation A drartflge StnKhmi be read.. tavqftgflfumplcw at scale of 1:5,000 he to be c^ed out wnsulution with the responsible experts on the proposed irrigable lands. All required and crnial sections) shall be prepared at required scales with one meter contour interval mid detail design of sample blocks shall be earned out 12 For all priaritited and selected irrigation sites, preliminary casting shall be made inc hiding for all engineering worts of die drvmion off-lake*, canah & drams? and other infT35tnjciures in order to estimate the cast of the whole project. This may include. r - estimation of development cost (casting of tertiary units) - cstimntion of major irrigation & drainage canals associated with major shudwe^. - estimation of abstraction systems ( head-works like dam for multi- purpose or irrigation development, diversion weir and pump EtationsJ - estimation of total project cost. 13. problem* of drainage, flooding, salinity or others shall be identified wherever is existing or expected to occur in the course of operation of irrigation projects, and thus proper solutions such is: appropriate drainage designs, flood protection works, land reclamation & soil management practices shall be proposed. 14, Plan Of dmlopmcnt xeoujM has to bt prepared with a guide Imc for water allocation fur normal condiliuns and extreme years. 15. Studies regarding small scale imgaQQn development projects shill be conduct with the rouDwmg points of emphasis. - Inventory of existing COnsMcd schemes dr those under constrain regarding small swfc unction projects shall be Ldcuuricd usini l:3aoao scale lopo-maps and aerial phoiog^aphs. 1 - Exh small «to station sites shill be visually footed as fat as p^ibte. ‘ tesien and rating Of ihepruposed schemes shall be u-uriert out. 16. to asrccmtnls (q be made. prepared Ind submitted according •**»*» nnnnV- ,r ■ *■ -ytrT.a <’»■ ’■-■■‘-■p-■ .-.-M 'u-Aa ■“■ '■ ■.■■>■.■ *’ ‘j1 .. 'j : - s r-.-. ■ ■ . ■ . "M® iftK." ■ f| -- B Br* «-r 3“TH I 1 ■ ■ ■•'■.•'• r Vr. . ' ■- " ■». “ ii J “ ■ •- .;V .7 -y-,,.- ■- ■ ■■ • > j- ‘"■'■‘ir'" ■ ■ ' , l ■. - ■' "J , =' r“ ■ Aythi Dry HajtfvMaster Fun Project Rftconnaiiwra lnigMog ADraimgc Report 31 References 1. APS <t XRDEP, 1995. Ttnt Depression Reconnaissance Study, Final Report Addis Abeba 2. CO* SAERAR, 1998. Irrigation Project Study for the Afar Reg. Stale, Executive Summary Bahir Dar. 3. CCFSAERAR A CECE. Kubo-Girana Valley Development Program Fearibility Study Report, Vol TV, Minerals, energy and water Resource Assessment, Final report. Addis Abeba, 4. FAO, 1995, Irrigation in Africa in Figures Waler Reports, Rome. 5. IPS, 19998 Resource Potential Study for Industrial Development in the Alar National Regional Slate, Vol. IV, Minerals, Energy and Water Resource ssessment. Final Report. Addii Abeba. 6. IPS & lhe Afar Deal of lhe prime MinLslers Office of the Social, Administrative & Regional Affairs Sector, 1998. Technical Proposal for lhe Feasibility Study of an integrated Development of the Tcm Area in the Afar Nabonal Regional State. Addis Abeba. 7. REST, 1998. Feasibility Study Report for the Raya Valley Agricultural Development Project, Vol n. Waler Resources AnneX’D Irrigation Development Plan 8. WAPCO5 & EVDSA, 1990. A Preliminary Water Resource Development Master for Ethiopia. Vol’ll Main Report. The Eastern Basins Addis Abeba. to Miruty ofWater Rewtees River Bsin Devefcajmient Studies Deputrr*it Juituary 2W0. H:: - ■ 1 '■ '
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